Objective To compare the difference among DNA damages in physics processes caused by protons with different energies around Bragg peak.Methods By constructing the nucleus and DNA model using Geant4 and simulating the transportation processes of protons with different energies around Bragg peak in nucleus model based on Geant4-DNA,the information of interaction points were recorded.16％ of them were picked randomly to use as the points at which protons interact with DNA.After finding out the points which broke the DNA and writing their information to new files,these new files were treated with density-based spatial clustering of applications with noise (DBSCAN),so as to analyze and calculate the difference of DNA damages caused by protons with different energies.Results With the protons with energies from 20.0 to 0.6 MeV,the numbers of damage points and damage clusters increased from 49.86 to 549.88 and from 2.92 to 82.46,respectively;the numbers of clusters with different sizes had a remarkable increase,and the number of clusters with size not less than 5 increased by 400 times.The average cluster size increased slightly.Simple single strand breaks (SSSBs),complex single strand breaks (CSSBs),simple double strand breaks (SDSBs) and complex double strand breaks (CDSBs) of DNA increased by about 8,26,24 and 64 times,respectively.The proportion of single strand breaks (SSBs) decreased from 96.69％ to 89.37％,and the double strand breaks (DSBs) increased from 3.31％ to 10.63％.Conclusions The lower proton energy would result in the more complex damage to DNA and the harder repair of DNA damage.

Objective To compare the diagnostic value of digital breast tomosynthesis (DBT) versus digital mammography (DM) in the evaluation mass like lesions in dense breasts. Methods Eight hundred and fifty eight patients, who had DBT and DM, with breast diseases confirmed by pathology were retrospectively reviewed. The breast density and the imaging features were classified according to the standard of American College of Radiology(2013) and breast imaging reporting and data system (BI?RADS) scores. Six hundred and thirty one patients with mass lesions in dense breasts were chosen to included. All 631 patients had DM of both breasts and DBT of affected breast prior to mastectomy. Pathological results were used as the golden standard. Detection rate and diagnostic accuracy of masses, sensitivity and specificity of diagnosis, false negative and recall rates, the margins and spicules and BI?RADS category were calculated. The detection rate and diagnostic accuracy, the margins and spicules of masses were compared with Chi?square test, the BI?RADS scores were analyzed with rank test. Results With DBT, average detection rate increased from 77.3%(488/631) to 84.3% (532/631), average diagnostic accuracy rate increased from 73.4%(463/631) to 82.3%(519/631),with statistical significant difference between groups (c2=27.191,36.890,P<0.01).Sensitivity for DBT and DM were 68.1%(205/301) and 58.8%(177/301), respectively. Specificity for DBT and DM were 95.2%(314/330)and 86.7%(286/330), respectively. Recall rate for DBT and DM were 3.6%(23/631)and 9.8%(62/631), respectively. One hundred and seventy two cases and 75 cases with circumscribed masses of benign cases were detected by DBT and DM, respectively. One hundred and eighty-two cases and 115 cases with spiculated masses of malignant cases were detected by DBT and DM, respectively, with statistical significant difference between groups (c2=70.471 and 21.707, P<0.01). Of 330 malignant cases, the numbers of BI?RADS category 0, 2, 3, 4A, 4B, 4C, 5 on DM images were 19,4,8,13,52,93,141, respectively, the numbers on DBT images were 3,1,7,5,52,83,179, respectively, with statistical significant difference(Z=-2.235,P=0.025). Of 301 benign cases, the number of BI?RADS category 0, 2, 3, 4A, 4B, 4C, 5 on DM images were 43,10,60,117,58,11,2, respectively, the number on DBT images were 20,4,64,150,55,7,1, respectively, with no statistical significant difference between groups(Z=-1.846,P=0.065). Conclusion DBT significantly improves the detection of mass?like lesions in dense breasts, display of mass margin and architectural distortion of surrounding tissue.

Objective To evaluate the efficacy and safety of actovegin against acute oral mucositis through a randomized controlled multicenter trial for nasopharyngeal carcinoma(NPC) patients treated by chemo-radiotherapy. Methods From February 2006 to May 2007,a total of 161 patients with newly diagnosed stage Ⅱ-ⅣA(1992 Fuzhou Stage) NPC were randomly assigned to the prevention group,the treatment group and the control group. All patients received current chemo-radiotherapy ± neoadjuvant chemotherapy. Radiation technique and dose were similar among the three groups. Intravenous infusion of aeovegin was started when radiation started in the prevention group and when grade 2 mueositis occurred in the treatment group,which was given 30 ml daily ,5 times per week until the end of radiotherapy. Criteria of NCI CTC 2.0 and VRS were used to evaluate acute oral mueositis and pain degree,respectively. Results 154 patients were eligible for the efficacy analysis,including 49 in the prevention group,53 in the treatment group and 52 in the control group. In the prevention group and the control group, the incidence was 31% and 56% (P=0.011) for grade 3-4 mucositis,59% and 83% (P=0.009) for grade 2-3 pain. In the treatment group and the control group,the corresponding number was 38% and 60% (P=0.023) ,70% and 90%, (P=0.014). The prevention group had a lower incidence(P=0.021) and longer average interval(P=0.009) of grade 2 mucositis when comparing with the control group. No drug-related adverse event was observed. Conclusions Prophylactic or therapeutic use of actovegin by intravenous infusion can significantly reduce the severity of ehemo-radiotherapy induced oral mucositis and pain. The prophylactic use may also postpone and decrease the incidence of grade 2 mucositis,which deserves clinic application.

Objective To evaluate the effect of intensity-modulated radiation therapy(IMRT) on parotid function in nasopharyngeal carcinoma(NPC). Methods Eighty-three NPC patients received prima-ry IMRT between 2001 and 2003. Xerostomia before radiotherapy, at the end of radiotherapy, at 6-month, 1-,2-,3-,4- and 5-year after radiotherapy were investigated, respectively. The relation between xerostomia and parotid dose distribution was analyzed. Results Of all the patients,4,31,31 and 17 had stage Ⅰ,Ⅱ,Ⅲ and ⅣA disease, respectively. Sixteen patients received chemo-radiotherapy. The median followed-up time was 65 months. The 5-year local control and regional control rate were 96% and 95% ,respectively. The 5-year overall survival rate was 80%. The mild xerostomia rate at the seven time points was 42%, 51%, 71%, 77%, 58%, 38% and 26%. The corresponding moderate xerostomia rate was 52%, 53%, 21%,8%, 3%, 2% and 2%, respectively. No serious xerostomia was observed. The mean dose of the bilateral parotid glands was 34.34 Gy. Xerostomia at 6-month after radiotherapy was positively correlated with the mean dose of the parotid glands, and D50 was the independent factor in predicting the xerostomia. Parotid function was well protected when the mean dose and D50 were no more than 33 Gy and 29 Gy,respectively. Conclusions IMRT can improve the local-regional control of NPC and protect the parotid glands from radiation-induced in-jury.

Objective To investigate the effective indicators for the prognosis assessment in pa?tients with multiple myeloma (MM) by 18F?FDG PET/CT imaging. Methods A total of 36 patients(22 males, 14 females;median age 63.5 years) with MM confirmed by clinical or pathology from July 2007 to November 2014 were retrospectively reviewed. The number of lesions detected by PET/CT, the number of lesions with SUVmax>2.5, the SUVmax and MTV of each lesion were calculated. The correlation analysis was performed between the number of lesions detected by PET or CT,the number of lesions with SUVmax>2.5, the SUVmax , MTV and serumβ2?microglobulin (β2?M) , respectively. The patients were divided into differ?ent groups according to the development of lesions and the survival situation during the follow?up ( 4-92 months) . Kaplan?Meier analysis and multivariate Cox model were used to analyze the prognostic significance of the number of lesions detected by PET or CT and the number of lesions with SUVmax>2.5, the SUVmax and MTV. Results Both the number of lesions with SUVmax>2. 5 and MTV showed positive correlations with blood β2?M (r=0.776, 0.954, both P<0.001), while the number of lesions detected by PET/CT and SUVmax were not correlated with β2?M ( r=0.053, 0.063, 0.398, all P>0.05) . The number of lesions with SUVmax>2.5 and MTV in the progressive group( n=14) were significantly higher than those in the regressive group(n=22):66.57±4.59 vs 31.95±4.75, t=4.95, P<0.001;(287.54±31.94) cm3 vs (72.17±14.35) cm3, t=6.93, P<0.001. The number of lesions with SUVmax>2.5 and MTV were significantly higher in the dead group(n=15) than those in the survival group(n=21):65.73±4.32 vs 30.90±4.87, t=5.10, P<0?001;(267.28±34.89) cm3 vs (76.39±15.67) cm3, t=5.49, P<0.001. The best cutoff values for predicting pro?gression?free survival and overall survival were both 42 for the number of lesions with SUVmax>2. 5, and those were 114.74 and 105.48 cm3 for MTV, respectively. The progression?free survival rate was worse in the patients with higher index than those with lower value (χ2=18.20, 29.74, both P<0.001) , and the same re?sult was also seen for the overall survival rate (χ2=19.07, 25.34, both P<0.001) . Conclusion The number of lesions with SUVmax>2.5 and MTV on 18 F?FDG PET/CT images could predict the progression?free survival and overall survival rates of patients with MM, which may provide accurate prognosis information.

Intestinal dysfunction can be induced under infection,trauma or stress. The intestinal mu-cosal barrier injury is a common pathophysiological process in critically ill patients. The bowel is one of the earliest and most severely affected organ under severe infection and tissue hypoxia-ischemia. Intestinal dam-age leads to a large number of bacterial flora shift,resulting in intestinal infection,intestinal endotoxemia and intestinal sepsis. In recent years,gastrointestinal barrier function has attracted people′ s attention,which is closely related to the prognosis of critically ill patients. This article described the normal intestinal barrier function,the effects of trauma and stress on intestinal barrier function,bacterial group migration,and the effects of endotoxin translocation on the body and its prevention and treatment.

Intestinal dysfunction can be induced under infection,trauma or stress. The intestinal mu＿cosal barrier injury is a common pathophysiological process in critically ill patients. The bowel is one of the earliest and most severely affected organ under severe infection and tissue hypoxia＿ischemia. Intestinal dam＿age leads to a large number of bacterial flora shift,resulting in intestinal infection,intestinal endotoxemia and intestinal sepsis. In recent years, gastrointestinal barrier function has attracted people′s attention, which is closely related to the prognosis of critically ill patients. This article described the normal intestinal barrier function,the effects of trauma and stress on intestinal barrier function, bacterial group migration, and the effects of endotoxin translocation on the body and its prevention and treatment.

Objective To analyze the efficacy of endoscopic ultrasonography-guided biliary drainage ( EUS-BD) for malignant obstructive jaundice and the management of adverse events. Methods Clinical data of 12 patients with malignant obstructive jaundice, who underwent EUS-BD between April 2016 and January 2017, were retrospectively analyzed. All patients received EUS-BD after unsuccessful ERCP, including EUS-guided hepaticogastrostomy ( EUS-HGS ) , EUS-guided antegrade stenting ( EUS-AS ) , and EUS-guided choledochoduodenostomy(EUS-CDS). Procedure outcomes, serum bilirubin and liver enzyme levels before the procedure and 1 week after, complications, treatment results, hospitalization time and follow-up were recorded. Results Two patients underwent EUS-HGS, 3 underwent EUS-AS, and 7 underwent EUS-CDS. Total bilirubin ( t=3. 462, P=0. 005 ) , direct bilirubin ( t=3. 351, P=0. 006 ) , alanine transaminase (t=2. 399, P=0. 037), γ-glutamate transpeptidase (t=3. 256, P=0. 031) reduced significantly after the procedure. Two patients ( 16. 67％) developed complications. A patient undergoing EUS-HGS developed bile leakage, biliary peritonitis, and pneumoperitoneum. A patient undergoing EUS-CDS developed upper gastrointestinal bleeding. Both patients were successfully treated. There were no other adverse events, such as acute pancreatitis, subcutaneous emphysema, pneumothorax and emphysema. No procedure-related death occurred. The mean hospital stay was 13. 75 ± 6. 92 days ( range 5-26 days ) . Conclusion EUS-BD is a safe substitute after unsuccessful ERCP when performed by experienced biliary endoscopists. However, intensive care is necessary after the procedure for early detection and management of complications.

Objective: Based on the MSM college students in Tianjin, this study aims to explore the demographic and behavioral characteristics of MSM with different sexual partners, and to provide evidence and information for intervention in combination with social networks. Methods: According to the source and access of seeking sexual partners, 546 MSM of Tianjin college students aged 18-24 in 2018 Jan. and 2019 Dec. were divided into internet-based MSM (396) and traditional MSM (150). Chi-square test and rank-sum test were used to compare the demographic information, sexual behavior characteristics, HIV prevention and testing awareness, and psychoactive substance use of the two MSMs, and Logistic regression was used to explore factors affecting college students use of the Internet for sexual partners. Results: Internet-based MSM has advantages in receiving HIV testing and safety consulting services, AIDS knowledge level, and peer education in the past year (P<0.05). The psychoactive substance use of the survey population reached more than 40%, and the awareness rates of pre-exposure prophylaxis and post-exposure prophylaxis were 32.98% and 55.32%, respectively. After multivariate Logistic regression analysis, MSM students who had received condom distribution, AIDS counseling and peer education (OR=2.16, 1.98, P<0.01) were more inclined to use the Internet for sexual partners. Conclusion Relevant departments can use the Internet to intervene in the prevention and control of MSM in colleges and universities in terms of AIDS-related knowledge, HIV testing, and mental substances.

In order to explore tick proteins as potential targets for further developing vaccine against ticks, the total proteins of unfed female Dermacentor silvarum were screened with anti-D. silvarum serum produced from rabbits. The results of western blot showed that 3 antigenic proteins of about 100, 68, and 52 kDa were detected by polyclonal antibodies, which means that they probably have immunogenicity. Then, unfed female tick proteins were separated by 12% SDS-PAGE, and target proteins (100, 68, and 52 kDa) were cut and analyzed by LC-MS/MS, respectively. The comparative results of peptide sequences showed that they might be vitellogenin (Vg), heat shock protein 60 (Hsp60), and fructose-1, 6-bisphosphate aldolase (FBA), respectively. These data will lay the foundation for the further validation of antigenic proteins to prevent infestation and diseases transmitted by D. silvarum.
Animals ; Antigens/*chemistry/immunology ; Arthropod Proteins/*chemistry/immunology ; Electrophoresis, Polyacrylamide Gel ; Female ; Ixodidae/*chemistry/immunology ; Molecular Weight ; Rabbits ; Tandem Mass Spectrometry